Manufacture of iron



Patented July 17, 1928 UNITED stars ATENT OFFICE.

MARK G. WOODMAN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-THIRD 'IO. DAVID G. FISHER AND ONE-THIRD TO VIVIAN F. SHANTZ, BOTH OF CHICAGO, ILLINOIS.

MANUFACTURE OF IRON.

No Drawing.

This invention relates generally to the manufacture of iron, and more particularly to a treatment Which is given to iron While in a molten state preliminary to the making of castings. By means of the present inven tion I am able to produce gray iron castings, the grain or texture of Which can be definitely controlled so as to obtain a product having desired properties.

The iron may be drawn in a molten state from the furnace into a ladle Where it receives an ad-dition of artificial salicylic acid in the suggested proportion of from one to three pounds per ton of iron. I find that iron so treated is purified, and its grain or texture is changed from coarse to one Which is uniformly fine and close, the product being thereby increased in hardness.

By the expedient just described, the properties of the iron are rendered definitely different'from those found in the usual gray iron castings. Not only is the grain closer and more uniform because of the salicyclic acid treatment, but the product isrendered more durable, more elastic, and is self-lubricating to a marked degree. It is susceptible of being machined, and When revolved in an oilless hearing will not develop any appreciable heat.

Serial No. 191,937.

I have found by experience that salicylic acid added to-molten iron within the suggested range of proportions Will produce most satisfactory results. For castings Which are to be machined, about 2 pounds of salicylic acid should preferably be added to each ton of iron. Changing the amount of salicylic acid Will produce a corresponding variation in the grain of the iron, i. e., the grain Will be finer and coarser if a greater amount of calicylic acid be added, and vice-versa. For this reason, it is entirely feasible to control the characteristics of iron castings When produced according to this invention.

I claim:

1. An improvement in the making of iron castings which consists in adding to the iron While in a molten state a quantity of salicylic acid.

2. An improvement in the art of making iron castings which consists in adding to the iron While in a molten state a quantity of salicylic acid in proportions ranging from' one to three pounds per ton of iron.

MAR-K G. WOODMAN. 

